vcmpequb.

Vector Compare Equal Byte (Record)

vcmpequb. VRT,VRA,VRB

Compares two vector registers element by element as unsigned bytes and sets the target vector register based on the comparison.

Encoding

Binary Layout

0:5

VRT

6:10

VRA

11:15

VRB

16:20

21:31

Format VC-form

Opcode 0x10000006

Extension VMX (AltiVec)

Operands

vD
Target
vA
Src A
vB
Src B
VRT
Target Vector Register
VRA
Source Vector Register
VRB
Source Vector Register

Example

vcmpequb v1, v2, v3

Registers Altered

CR6

Reference

View in PowerISA v3.1C Specification ↗ OPF Power ISA v3.1C

Description

The Vector Integer Compare instructions compare two VSRs element by element, interpreting the elements as unsigned or signed integers depending on the instruction, and set the corresponding element of the target VSR to all 1s if the relation being tested is true and to all 0s if the relation being tested is false.

Operation

if MSR.VEC=0 then Vector_Unavailable()
all_true ←1
all_false ←1
do i = 0 to 15
    src1 ←VSR[VRA+32].byte[i]
    src2 ←VSR[VRB+32].byte[i]
    if src1 = src2 then do
        VSR[VRT+32].byte[i] ←0xFF
        all_false ←0
    end
    else do
        VSR[VRT+32].byte[i] ←0x00
        all_true ←0
    end
end
if Rc=1 then
    CR.field[6] ←all_true || 0b0 || all_false || 0b0

Programming Note

vcmpequb[.], vcmpequh[.], vcmpequw[.], and vcmpequd[.] can be used for unsigned or signed integers.